Vasseur started work as Ferrari team principal in early January after the Scuderia parted ways with former team boss and long-time engine engineer Mattia Binotto at the end of its promising but ultimately disappointing 2022 campaign.
The move reunited Leclerc and Vasseur after the former made his F1 debut with Alfa in 2018, having also raced for Vasseur's ART Grand Prix junior team in GP3 in 2016 – winning that championship as a rookie.
"I was very impressed by how well he introduced himself in the team," Leclerc said of his new team boss.
"Ferrari is very different to whatever we are used to before. Ferrari is huge. And once he got here, he understood extremely well the way Ferrari works from the first few days.
"He's very clear in what he wants and he's extremely good at putting the people in the right mindset and in the right ambiance to give their best. And this is very important.
"So, that's what he brings to Ferrari and I'm sure it will be a good thing."
Leclerc was speaking at Ferrari's highly praised 2023 team launch, where he completed the first shakedown laps of the SF-23 before handing over to teammate Carlos Sainz.
After undertaking his two tours of Ferrari's Fiorano circuit on demonstration Pirelli tyres in front of a grandstand full of fans, Leclerc faced the media.
He was asked about his contract status with Ferrari, with his current deal running until the end of 2024.
But Leclerc insisted with two full seasons still remaining on that agreement, it is currently too early to even discuss the possibility of an extension or consider any decision about finding a new F1 drive elsewhere.
A new deal ahead of 2025 would be an interesting time for Leclerc with or without a move away from Ferrari, as Mercedes is yet to agree to a long-term new deal with Lewis Hamilton, Lando Norris's contract with McLaren runs out at the same time and Audi will be about to enter as a works operation following its buyout of the Sauber-run Alfa squad.
"Speaking about my renewal in Ferrari, it's not something that I've been particularly thinking [about] already," Leclerc explained.
"It's still a long way to go – two years. I will, of course, do my best.
"Not for the negotiations, but for myself and for the team. And then I will of course… you will know, for sure, when talks start. But it's not the time yet."
